The question presents a case of a 32-year-old female with a long-standing history of tobacco chewing since the age of 14. The key symptoms noted are restricted mouth opening and the absence of oral ulcers. We are asked to identify the most probable diagnosis. Let's evaluate the given options:
- Oral Submucous Fibrosis: This is a chronic, insidious oral condition associated primarily with tobacco chewing, especially areca nut. Restricted mouth opening or trismus is a common symptom due to fibrosis of the submucosal tissues. The absence of oral ulcers is consistent with this diagnosis.
- Lichen Planus: This is typically characterized by white, lace-like lesions in the mouth, known as Wickham's striae. Patients often have oral ulcers or erosive lesions, which doesn't align with the case details provided.
- Oral Thrush: Oral thrush is a fungal infection in the mouth, characterized by white patches or plaques. It is not commonly associated with restricted mouth opening, making it an unlikely diagnosis.
- Carcinoma of the Buccal Mucosa: This could present with restricted mouth opening if there is significant tissue involvement or fibrosis; however, it would likely present with visible lesions or ulcerations, which are not mentioned in the case.
Considering the patient's long history of tobacco chewing and the symptoms of restricted mouth opening without oral ulcers, the most probable diagnosis is Oral Submucous Fibrosis.
Thus, the correct answer is: Oral Submucous Fibrosis